Means for defrosting refrigerating units



Sept. 15, 1936. N. F. FRETTER 2,054,460

MEANS FOR DEFROSTING REFRIGERATING UNITS Filed July 4, 1933 2 Sheets-Sheet 1 Sept. 15, 1 936. F TTER 2,054,460

' MEANS FOR DEFROST ING REFRIGERATING UNITS Filed July 4, 1933 2 Sheets-Sheet 2 Patented Sept. 15, 1936 PATENT orrics mus non nnmosrmo nnrmonnsrnvo- UNITS Nathan Fretter, Cleveland Heights, Ohio Application July 4, 1933, Serial No. 679,008

17 Claims. This invention relates to refrigerating apparatus and more particularly to a novel means.

for defrosting the evaporator-or refrigerating unit thereof.

My defrostingmeans is particularly, thoughnot exclusively, intended to be used in connection with mechanically refrigerated apparatus or systems. The exemplified application of my invention consists of a refrigerator casing or cabinet wherein is provided a refrigerating unit which may include a series of trays removably placed therein. V

One object of this invention is to provide improved means, that. are relatively simple, durable and inexpensive in construction, for de-' frosting the refrigerating unit.

Another object is to provide an improved refrigerating unit defrosting means which can be operated quickly and without stopping the operation of theunit,- thereby saving time and continuously maintaining the refrigerator. I Another object of the invention is to provide a removable shield for and in contact with the refrigerating unit and providing a surface on which frost may accumulate; so that its removal efi'ects defrosting without afiecting the temperature of the areas or chambers in the refrigerator and/or stopping the operation of the refrigerating unit.

Another object of the invention is to provide an improved defrosting device which lends itself to evaporators sus'pendedfrom a horizontal, for

example the top, wallof' a refrigerator cabinet,

such device being so constructed that it may be Fig. 1 is a fragmentary sectional view througha portion of a refrigerator or cabinet showing therein a refrigerating unit and a defrosting means embodying my invention, parts being broken away.

Fig. 2 is a side elevation of the parts shown in F s- 1. i

Fig. 3 is a bottom plan view on the line 33 of Fig. 2. I

Fig. 4 is a perspective view of the defrosting device.

Fig. 5 is a fragmentary section on the line 55 of Fig. 2.

a. low temperature in Fig. 6 is a view similar to Fig. 1, but showing a modified form of construction. g V

Fig. 7 is a side view of the parts shown in Fig. 6.

Fig. 8 is a bottom plan view on the line H of Fig. 7.

Fig. 9 is a plan view of the device shown in. Figs. 6, 7v and 8, with its sections separated.

Fig. 10 is a fragmentary front elevation of parts shown in Fig. 6, enlarged.

In the drawings, a portion of a refrigerator 10 is shown. i denotes generally the rear and side walls, 2 the top wall and 3 a portion of the front 7 wall of the refrigerator, these walls being constructed in a manner well known in the art to minimize heat transfer. The front" wall is pro- 15 "vided with a door 4' providing access to the space 5 within the refrigerator and the refrigerating unit 6. 1. indicates ice trays'of the ordinary construction and slidable outwardly and inwardly, the handles 8 serving as the operating means 20 therefor. The refrigerating unit, as shown is secured to the top wall 2, being suspended therefrom by suitable hangers-i. In Figs. 1, 2 and 5,.the refrigerator unit or evaporator 6 comprises a pair bf spaced chambers Ga and a coil arrangement ,6 herein'illu'strated as consisting of an inner plate to and an outer corrugated plate 60 fixed to the inner plate in a well known manner to form the conduits Be in communication with the chambers 60.. The coil arrangement, as shown in Figs. 1 and 2, is shaped to provide spaced parallel sides and a bottom, forming a. space forthe trays l, the walls to being provided with laterally pressed ribs to form guides for the trays. The rear end of the coil arrangement below the chambers 6a may be provided with an end strip 9, which. may form an abutment as later set forth.- A suitablevolatile liquid refrigerant is supplied tothe chambers 6a, to, under control of a float actuated valve (the supply pipe, float chamber, float and valve not being shown). of any desired construction. The chambers 6a, 6a, are provided with exhaust pipes I0, connected to a common exhaust pipe II, which may lead to the intake of a compressor (not shown). As is customary in refrigerating apparatus of this type, the volatile liquid refrigerant is supplied to the chambers to. from which it flows into and through the conduits 6e and vaporizes. The vapors rise in these conduits into the chambers 60. where they become separated from the liquid and flow into the pipe ll, due to the suction'effeet therein. I

It indicates my defrosting device adapted to be removably related to the coil arrangement 6' and having a cross sectional shape corresponding to'the cross sectional shape of the, coil arrangement 6' and preferably having-corrugated walls 6c, whereby intimate thermal contact between substantially the entire area of the walls of the device I2 with the walls 6c results and entrance of moisture (free moisture or vapor) between the device and coil arrangement 6' is prevented.

Furthermore, the complementary corrugated walls serve as guide means in positioning the de vice. However, where the coil arrangement consists of a plurality of depending pipe loops or coils,

- Figs. 1 and 2; and when so positioned it will be seen that vapor and free moisture circulating within the cabinet will, when precipitated as frost, snow or ice, accumulate on the exterior surface of the device I2, which, being removable, permits defrosting to be effectively and quickly carried out. For example, the device I2, when removed may be thrust into a body of water, or sprayed with water and then re-positioned, or another device may be substituted. As the frosting occurs on the exterior-walls of the device I2 and not on the walls of the coil arrangement 6,-

removal of the food and/or stoppage of the refrigerating unit 6 is not required, so that the refrigerated atmosphere in the cabinet is continuously maintained for an indefinite period,

Upon operation of the detachable means, the

initially swung laterally (see dotted lines in Figs.

1 and 4) to disengage them from the coil arrangement 6'. The hinge connections comprise plates I8 alternately spot-welded to the adjacent marginal portions of the sections I2a and provided with alined knuckles to receive a pivot pin or rod I6, the outer end of which projects beyond the sections to form a handle Ila. The inner and outer hinge plates I3 and adjacent portions of the respective other sections |2a are provided with pairs of angles (spot-welded thereto) having related walls I5 which serve as stops to limit the lateral swinging of the sections I2a.

The detachable means comprise the following; I6 indicates a pair of alined bearing members disposed at either side of the refrigerating unit adjacent the upper ends of the coil arrangement 6 and disposed outwardly of the plane in which the side walls of the device I2 are disposed when in position. Each member preferably consists of a plate spot-welded to the hangers I' and provided with projecting spaced lugs l1, II, the lower lug I'I' forming a seat. I8, I8, indicate connectors swingahly mounted on 0:: free ends of the sections I2a and each having P r ions which removably engage the adjacent seats II'. As shown in Figs. 2 and 4, each connector I8 has (a) an intermediate portion I8a rotatable in a knuckle I8 provided on the end of a wall 26 extending upwardly from the adjacent section I24 (b) oil-set end portions Ilb adapted to be inserted between the lugs l1, l1, into the seats formed by 1 the latter lugs. The outer endof the connector is provided with ahandle 2|. I'o position the device I2, it is engaged with the coll arrangement 6'- against the abutment 8 and the cit-sets Ilb are engaged in the seats I1; next the handles 2| are operated to rotate the off-sets [8b in the seats H, which operation swings the portions I8a upwardly and inwardly against the hangers I. As the portions IBa rotate in the knuckles I8 and are connected through the latter to the upthe device against the coil arrangement 6' and I the connectors will be locked in position. Operation of the handles in the opposite direction will release the connectors 18 and swing the sections .I2a, 12a, outwardly away from the coil arrangement so that the device I2 may be removed.

Figs. 6 to 10, inclusive, show a modified form of construction in which the refrigerating unit 62 consists of a single volatile liquid chamber 51" and the upper ends of the coil arrangement are turned inwardly, the liquid refrigerant being supplied by a pipe 22 and the gas or vapors being exhausted through a pipe 23 and the unit being suspended by a pair of hangers Ir. The lateral sides of each hanger la: are extended and provided with inverted contiguous cam.wa1ls 24a, 241), the purpose of which will later appear. As shown, the defrosting device I2: is shaped to fit the coil arrangement 63: and carries at the upper end of each side wall a connector I80: having a. handle I8a:', each of said ends being provided with spaced knuckles 25 in which the adjacent connector rotates. Between the knuckles 25, the connector I81: is provided with off-sets 26, each in alined relation to one of the cam walls and arranged to engage therewith when the adjacent connector is operated. In positioning the device I2x, it is positioned in engagement with the coil arrangement is, with the oflE-sets 26 at the inner ends of the cam walls 26a, 24b. By operation of the handles 182:, the connectors I8: are rotated in the knuckles 26, the effect of which is to swing the off-sets outwardly into engagement with the cam walls 24a, 24b and as the operation of the handles continues the cam walls 24a, 26b acting through the off-sets 26 will force inwardly the end portions of the device I2: to the limit of their move-- ment, the effect of which is to lock the connectors in operated position. In the reverse movement of the handles, the off-sets 26 will engage the cam walls 24a, 246, which will serve to swing the sections of the device I20: away from each other, so that the device can be readily removed.

To those skilled in the art to which my invention relates, many changes in construction and widelydlifering embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. My disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

What I claim is;

1. In a refrigerating mechanism, the combination with an evaporator, of, a sectional defrosting device formed of sheet metal and having a bottom and side portions arranged to fit over said evaporator in therma1 contact therewith, and

ing thermal contact with said evaporator, and quick operating mechanism connected thereto for securing said device in position.

3. In a refrigerating mechanism, the combination with an evaporator, of a sheet metal device comprising hinged sections arranged to fit over said evaporator in thermal contact therewith, and means on the terminating ends of. said sections for detachably securing said device in posi- I said evaporator, and detachablev means for securing said device in position.

6. In a refrigerating mechanism, the combination with a support and an evaporator supported thereby, of a sectional defrosting device formed of sheet metal and corresponding in. cross sectional shape to the cross sectional shape of said evaporator and arranged to be positioned thereover in thermal contact therewith, and quick operating mechanism connected thereto for securing the said device in position.

7. In a refrigerating mechanism, the combination with a support and an evaporator supported thereby, of a sectional defrosting device formed of sheet metal and having a bottom and side portions arranged to fit over said evaporator in thermal contact therewith, and a crank actuating mechanism secured to each. side portion for detachably securing said device in position.

8. In a refrigerating mechanism, the combination with a support and an evaporator supported thereby, of a .sheet metal device comprising hinged sections arranged to fit over said evaporator in thermal contact-therewith, and means on the terminating ends or said sections for detachably securing said device in position, said sections being swingable about their hinges to permit removal and positioning of said device.

9. In a refrigerating mechanism, the combination with a support and an evaporator supported thereby, of a sheet metal device comprising hinged sections arranged to fit over said evaporator in thermal contact therewith, and means on the terminating endsof saidsections for detachably securing said device in position, said sections 'being swin'gable about their hinges to permit removal and positioning of said device and means for limiting the movement of said sections away from each other; a 10. In a refrigerating mechanism, the combination with a support and an evaporator supported thereby, of a sheet metal device comprising a pair of hinged sections arranged to fit over said evaporator .in thermaLoontaet therewith and swingable laterally to permit removal of said device, the pivot pin. of the hinges for said sections being extended to form a handle, and

means for detachably securing said device in position. I

11. In a refrigerating mechanism, the combination with a refrigerating unit comprising a chamber and a coil arrangement, of a sheet metal device having corrugated sideand bottom walls-arranged to fit over said coil arrangement in thermal contact therewith, said device comprising hinged together L-sections and detachable means for connecting the upper ends of said sections to the upper portion of said coil arrangement.

12. In a refrigerating mechanism, the co bination .with a support and an evaporator supported thereby, of a sheet metal device fitting and having thermal contact with said evaporator, and detachable means for securing said device in position, said means comprising seat members and connectors having portions rotatably mounted on said device and off-set portions arranged to detachably engage said seat members and swingable into locking position.

13. In a refrigerating mechanism, the combination with a support having supporting elements and an evaporator supported by said ele-' ments, of a sheet'metal device comprising relatively movable connected sections having thermal contact with the heat exchange walls of said evaporator and removable therefrom to effect defrosting, and means engaging said supporting elements for detachably securing said device in position.

14. In a refrigerating mechanism, the combination with a support having supporting elements and an evaporator supported by said'elements, of a sheet metal device corresponding in cross sectional shape to the cross sectional shape of said evaporator and comprising hinged sections and arranged tobe positioned over and in thermal contact with said evaporator, and

detachable means engaging said elements for securing said device in position.

15. In a refrigerating mechanism, the combination with an evaporator, of a device comprising hinged-together sections shaped to thermally contact therewith and adapted to serve as frost collecting surfaces, and a cam mechanism for relatively moving said sections to clamp and release them in relation to said evaporator.

16. In a refrigerating mechanism, the combination with an evaporator, of a device'eomprising hinged-together sections shaped to thermally contact therewith and adapted to serve as frost collecting surfaces, and a toggle-joint mechanism for relativelymoving said sections to clamp and release them in relation to said evaporator.

17. In a refrigeration mechanism, the combination with an evaporator. of a removable defrosting device formed of heat conducting mate'- rial and comprising relatively movable connected sections arranged to engage with and enclose the side walls of the evaporator from end to end thereof, and attaching means carried by the said sections.

' NATHAN I. ran-rm. 

